Accelerated life tests (ALTs) are widely used in many applications for the time-effective assessment of products. Statistical analysis of the performance degradation paths of the products combined with actual failure times have the competence to provide more accurate lifetime estimates. We propose two nonparametric methods for analyzing the ALT data where the degradation paths and failure times...

The Cox proportional hazards model has become the model of choice to use in analyzing the effects of covariates on survival data. However, this assumption has significant restrictions on the behavior of the conditional survival function. The accelerated failure time model, which models the survival time and covariates directly through regression, provides an alternative approach to interpret th...

It is a common understanding that fat-free mass (FFM) increases with body weight. However, limited information is available as to the relationship between weight increase and changes in body composition. We performed the present study to determine quantitatively the relationship between body composition, total body weight, age, and sex. Body composition data were obtained by isotopic dilution o...

A number of approaches have been developed for analyzing incident clearance time data and investigating the effects of different explanatory variables on clearance time. Among these methods, hazard-based duration models (i.e., proportional hazard and accelerated failure time models) have been extensively used. The finite mixture model is an alternative approach in survival data analysis, and of...

Component-based software development allows developers to compose applications using software parts, called components. This approach represents an important step towards reducing development cost and time, and allows the creation of automated tools for software development. However, current applications have quality of service (QoS) requirements, and the existing component-based technologies p...

BACKGROUND Gastric cancer is the one of the most prevalent reason of cancer-related death in the world. Survival of patients after surgery involves identifying risk factors. There are various models to detect the effect of risk factors on patients' survival. The present study aims at evaluating these models. METHODS Data from 330 gastric cancer patients diagnosed at the Iran cancer institute ...

Previous studies have shown that the effective rocker shape of the physiologic ankle-foot system during standing and fore-aft swaying is much flatter than that used during walking, which indicates a more stable base of support for the standing/swaying activity. Previous work suggests that flat regions within the effective rocker shapes of prosthetic ankle-foot systems could provide enhanced sta...